Sarcopenia and modified Glasgow Prognostic Score predict postsurgical outcomes in localized renal cell carcinoma

Background: Body composition and inflammation are gaining importance for prognostication in cancer. This study investigated the individual and combined utility of the preoperative skeletal muscle index (SMI) and the modified Glasgow Prognostic Score (mGPS) for estimating postoperative outcomes in patients with localized renal cell carcinoma (RCC) undergoing nephrectomy.

Methods: The authors performed a retrospective review of 352 patients with localized RCC. SMI was measured via computed tomography or magnetic resonance imaging. Patients met the criteria for sarcopenia by body mass index- and sex-stratified thresholds. Multivariable and Kaplan-Meier analyses of associations of sarcopenia and mGPS with overall survival (OS), recurrence-free survival (RFS), and cancer-specific survival (CSS) were performed. Variables were analyzed independently and combined into risk groups: low risk (nonsarcopenic, low mGPS), medium risk (sarcopenia only), medium risk (inflammation only), and high risk (sarcopenic, high mGPS). Receiver operating characteristic (ROC) curves were used to analyze risk groups in comparison with the Stage, Size, Grade, and Necrosis (SSIGN) score and the modified International Metastatic RCC Database Consortium (IMDC) score.

Results: The majority of the patients were at stage pT3 (63%), 39.5% of the patients were sarcopenic, and 19.3% had an elevated mGPS at the baseline. The median follow-up time was 30.4 months. Sarcopenia and mGPS were independently associated with worse OS (hazard ratio for sarcopenia, 1.64; P = .006; hazard ratio for mGPS, 1.72; P = .012), CSS, and RFS. Risk groups had an increasing association with worse RFS (P = .015) and CSS (P = .004) but not OS (P = .087). ROC analyses demonstrated a higher area under the curve for risk groups in comparison with the SSIGN and IMDC scores at 5 years.

Conclusions: Sarcopenia and an elevated mGPS were associated with worse clinical outcomes in this study of patients with localized RCC. This has implications for preoperative prognostication and treatment decision-making.

Lay summary: Kidney cancer is a disease with a wide variety of outcomes. Among patients undergoing surgical removal of the kidney for cancer that has not spread beyond the kidney, many are cured, but some experience recurrence. Physicians are seeking ways to better predict who is at risk for recurrence or death from kidney cancer. This study has evaluated body composition and markers of inflammation before surgery to predict the risk of recurrence or death after surgery. Specifically, low muscle mass and an elevated inflammation score (the modified Glasgow Prognostic Score) have been associated with an increased likelihood of recurrence of kidney cancer and death.